| 摘要 |
The present invention is to provide an exhaust gas purification catalyst apparatus, which is superior in oxidation performance of, in particular, nitrogen monoxide, among hydrocarbons, carbon monoxide, nitrogen oxides and particulate components such as soot, included in exhaust gas from a lean burn engine, and combustion performance of light oil. The present invention is an exhaust gas purification apparatus arranged with an oxidation catalyst (DOC) comprising a noble metal component for oxidizing carbon monoxide, hydrocarbons, in particular, nitrogen monoxide among nitrogen oxides, and for combusting light oil, a catalyzed soot filter (CSF) including a noble metal component for collecting a particulate component such as soot and removing by combustion (oxidation) it, a reducing agent spraying means for supplying a reducing agent selected from a urea component or an ammonia component, and a selective reduction catalyst (SCR) not-including a noble metal for removing by reduction of nitrogen oxides (NO x ) by contacting with the reducing agent, in this order from the upstream side of an exhaust gas passage, in order to purify carbon monoxide, hydrocarbons, nitrogen oxides, and particulate components such as soot, in exhaust gas discharged from a diesel engine, characterized in that the oxidation catalyst (DOC) has a catalyst layer where platinum (Pt), palladium (Pd) and barium oxide (BaO) are supported on alumina (Al 2 O 3 ) having a pore size of 12 to 120 nm, and ratio of platinum and palladium is 1:1 to 11:2 in weight equivalent. |
